A review of automatic vehicle location technology and its real-time applications

A combination of technological advances in systems which track buses and the continuing fall in prices of computing hardware has led to Automatic Vehicle Location (AVL) systems becoming an attractive and affordable proposition for many bus operators. However, AVL technology is still relatively new to the bus industry and little research has been carried out as to the potential benefits of these systems. AVL systems can be based on a variety of technologies, namely, dead reckoning (odometer and compass). beacon and either lag or radio; radio triangulation (using a network of ground-based transmitters), or Global Positioning System satellites. Many factors need to be considered before specifying an AVL system, but the type of technology on which the system is based is probably the most important for many applications.